Electbic ftjrnace



May 19, 1925. 1,538,365

E. L. WILLSON ELECTRIC FURNACE Filed Oct. 16, 1922 3 Sheets-.Sheet l QMM m f NQ .www

.\.. m1, mm. m m

May 19', 1925. Y 1,538,365

E. L. WLLSON ELECTRIC FUnNA Filed Oct. 16. 1922 3 Sheets-Sheet 2"Hllnwf' f5- @MAM/tin May 19, 1925.

E. L. WLLSON ELECTRIC FURNACE Filed Oct. 16

. 1922 3 Shee'ts--Sheei'l 3 Il l Hilllh Patented May 19, 1925 UNITE'DSTATI-:s

1,538,365 PATENT orrics.

EDwpi L. wmLso'N, or FARMINGTON, coNNEc'rIcUT.

ELECTRIC summer.

pplicationvled October "16, 1922. No. 594,831.

To allhomit'may concern:

Be it known that I, EDWIN L. llVxnnsoN, a citizen of the United States,residing at Farmington, county of Hartford, and State of Connecticut,have invented new and useful Improvements in Electric Furnaces, of whichthe following'is'a full, clear, and ex act specification.

My invention relates to furnaces and refers particularly to electricallyheated furnaces.

The object of my device "is an internally electrically heated rotary'furnace ca able ofa continuous process of heating artic es autolmatically at any desired temperature for any desired period of timeeither with. or without, the presence of air, carbonizing gases; ineitor other gases. Y 1

Considerable difficulty -has' been experi- "3 enced in obtaining.uniform temperature, hardness, bluing and other similar results upon aplurality of small articles. due tothe diiculty in obtaining anaccurately uniform temperature and duration of treatment inthe heatingprocess.

As the desired results depend upon the temperature and time of heattreatment and are affected by any variation thereof, it is evident thatuniform results can be obtained only when each and every article hasbeen subjected to the same heating temperature for the same length oftime.

The difiieulty of thus treating a large` number of such small articles,as bearing balls,fchain links and other small parts, is evident and adevice capable of accomplishing these results is-a. most valuableadvance in the heat treatment of metal articles.

vThe device of my invention is capable of producing all of thesedesirable results in a most efficient and economical manner andcomprises in a general way a rotary furnace, electrically heatedinternally, the interior heat of the furnace being autonniticallycontrolled and the process of treatment being pieferably continuons? Theaccompanying drawings, illustratingr modified forms of the device of myinvention and are given for the purpose of more clearly defining myinvention, similar parts being designated by similar numerals.

. Figure 1 is a cross-section through the line 1-,1 of Figure 2. thedot-and-dash lines illustrating the position of the driving mechanism.

Figure 2 is al cross-section through the line 2-2 of Figure 1-showing-aportional end view of Figure 1. v

Figure 3 is a cross-section throughl the line 3-3 of Figure 1.

4 is a cross-section through thc line 4-4"of Figure 1. .A Figure 5 is avertical cross-section ofa modified form of the device of my invention.

The particular form of the device of my 05 invention, shownin Figures 1,2, 3 and 4 of the accompanying drawings, comprises a bed 10 carrying'the supports Il, 11, within the bearings 12, 12 of which is therevoluble shaft 13.' .Fixedly attached to theshaft 13 70.

`is thc'toothed worm: wheel 14 and the fric-V tional flanged bearingwheel 15. The worm wheel 1.4 meshes'withi'the worm 16, carried by thebearings 17, 17, the shaft 18 of the worm 16 being connected with asource of 75 rerolnble power. not shown.

Each of Athe other three corner portions of the bed 10 carries brackets19. 19 having bearings 20, 2O in. which is a shaft'Zl carrying a freelyrevoluble flanged idler 22.

The legs 23, 23 carry tlie pillow blocks 24, 24 which support thenon-revolublc tubular member 25. A hopper 26 opens into thetubnlarmember 25 and a pipe 27,'connected with a source of suitable gas supply,notfg shown, passes through a portion o'f the tubu-v hr member v2.5 andis then bent downwardly within the furnace. i

The een ra'l portion of the tubular member 25 passes t irough andcarries a pluralit)- of 90 wirt` carriers '28. 28, composed preferablyof heat refractory. electric insulating and heat insulating material,the carriers being maintained in position by a series of supporting rods29, 29. The wire carriers 28, 95 2S have a plurality of extended arms30` 30 to which a wire may be attached by any suitable means.

Revoluble around the .tubular member 25 is a container composed of theannular front end 31. Fixedly attached to the end 31 by means of bolts32. 32 is the flat ring 33. 'ithin the interior opening of the ringmember 33 is the cylindrical furnace side 34. The ,other end of thedevice comprises the annular members 50, 37 fixedly attached to tthetubular member 25 which passes through the opening 38 by the member 37.

An arm of the annular member 39 is inserted within an annular recesswithin a re- 11 cess within'the member 35, the other right hfrledannular arm of the member 39 being bolted at 40 to the flat rino' member41. The other extremity ofthe supported bythe opening within the'ring'meinber 41.. 'A

fi"-- li`.ixedlv attached to the interior .face of the revo uble furnaceside is a helixshaped member 42 having a central opening to allow of itsbeing spaced from the wire carriers 28, 28. I

An opening 43 isformed within the lower portion of the end member 36 andthe sides thereof extendedinto the tubular member 44, the lowerextremity of which is-below the surface of the oil or other quenchingmaterial 45 in the container 46.

The electric heating,- or resistant, wire 47 is wound around the wirecarrier arms 30, and extends outwardly through the tubular member 25 andis connected with any suitable means for the supply of electricalcurrent, this end of the tube 25 being closed. A pyrometer 48 isintroduced into the tube 44 and a pyrometer 49 is inserted within theworking chamber and the latter. may be connected vto any suitablethermostatic device for the control of a uniform temperature.

The following method is employed` in order to prevent, or reduce, theloss by heat radiation f The chamber formed within the members` 35,- 50,37 is packed with a non-conductor of heat. An annular chamber is lformed at the other end of the furnace by means of the plates 51, 52 and53 and filled with a nou-'conductor of heat.

annular plate 54 is fixedly attached to the plate 33, an annular plate55 is' fixedly attached; to the plate 41 and a telescopicf annular plate`56 is horizontally slidable within the plates 54 and 55 and the chamfrthus formed is filled. with a nop-conducof heat. This formation allowsof horital movementdue to heat expansion.

n annular plateV 57 is attached to the lates 41 and 39 and the chamberthus ormed is filled with a non-conductor `of heat.

The wire carrier nearest the forward end of the furnace and-throughwhich the pipe 27 passes is somewhat different in construction from theothers in that it has opening 58 (Figure 4) extending downwardly fromthe central opening in order to allow of the passage of the pipe 27 andfor the introduction of articles to be heated.

The end members 33 and 41 of the furnace bndy'rest upon the frictionalwheel -15 and the idlers 22. 22; 22 so that the revolution of thefrctional wheel 15 will revolve the furnace hody with its atta hedparts.

The operation of the evice as described is as follows Revoluble movementis imparted to the furnace side' v25 is' l passa .under props;

shaft18,the worm 16, the gear wheel 14, the shaft 13 and the frictionalwheel 15, which thus revolves the furnace with its non-conductincovering and attached helix 42, aroun the tubular member 25 and the wirecarriers 28,'28. An electric current is then assed through the resistantwire 47 heatmg the interior of the furnace to any desired temperature.The objects to be heated, as, for instance, bearing balls 60, 60 areintroduced through the ho per 26 and the tubular member 25 from whichthey drop into thefurnace, their passa-ge through the tubular member 25beyond the point of introductionV into the furnacebeing prevented by thebale plate 59. The helix 42, during its revolution, carries the balls60, 60 along the lower.portion of the furnace, heating them v to anydesired temperature and time of treatment dependent upon the temperatureof the furnace andthe time required for therethrough, the latter beingcontrol '.by the length of the furnace and the rate of revolution of thehelix. The heated balls pass through the opening 43 and the exit ipe '44into the oil 45, where they are caug t by the foraminous basket 61,

`which can be removed when desired.

It is. to be noted that during the heating operation the furnace space,its side wall andthe objects therein are subjected to the full effectsof the-heated wire and any cooling effect, caused to the lower portionof the furnace wall due to heat absorption by the objects, will'becounteracted' during t e remainder-.of the revolution of the fur- Anyheating effect, which will'he small l conditions, caused by the tu-lbular mem r 25 will act as a preheater for the introduced objects.

The air in the furnaceA may be partiallyt or completely, removed by thevapors arising from the oil 45,l due to the introduction of the heatedobjects, the fumes arising throughthe pipe 44 into the furnace, thusdriving the air outwardly through the tubular member 25.

My device is also admir'ably adapted for carbonizing processes, in whichcase a suitablel carbonaceous gas may be introduced through the pipe 27,or a' suitable carbonizing compound may be introduced into the' furnace,the heat of which will cause an evolution of the carbonceous gas. A

VThe form of my device, described above,

is suitable for the heating of small objects moved within the furnace bymeans of the described helix, bui d modification is de.

4described.articles is shown in Figure 5 in similar to t which theeneral form of the furnace is at previously described, except that thehelix .42,.is removed, a hinged door is -introduced'at one end .of thefurnace for pur oses lof introducing the articles and a hinged door 71is introduced at the other end of the furnace for purposes of withdrawalof the -articles after' the heating treatment and the end' 35, 36, 3f?'is re vlaced by the annual end 72.I Pro r insu ating devices may beemployed as esired, similar to those shown in the prior res.

It is evident that means ot er than the -disclosed helix may be emplo edfor producing a movement of the articles through the furnace. Y Thedegree of applied heat and the duration ofthe treatment naturally dependupon the objects treated and the results desired and my device is ofsuch construction -that it can be readily adapted to any desiredlprocess of operation and maintained under uniform conditions during thetreatment of any desired number of articles.

By electric wire as used in-my s ification and clamsI mean any wire, ribon or other electrical construct'io' means, having electric resistanceunder 'the conditions of employment to produce? the desired heat.

My device, therefore,presents many novel and valuable features@ for theheat treatment of small metallic articles and parts.

I do not limit myself to the particular size, shape, number, arrangementor material of parts, as shown and described, as they are given' sim ly'as an example for the clearer explanation of the device of myinvention. l

What I claim isgfy 1. In an internally electrically heated rotaryfurnace, in combination, a revoluble furnace having an opening for theintroduction of material and an opening for the removal of saidmaterial, means for'revolving the furnace, wire carrying means withinthe furnace and a wire -carriedthereon and extended outwardl of thefurnace.

2. In an internally e ectrically heated rotary furnace, in combination,-a revoluble furnace having au opening for the intro-` duction ofmaterial and an opening for the removal of said material, means forrevolving the furnace, stationary wire carrying means within thefurnaceand av wire cui-, outwardly of the ried thereon and extended furnace. l

3. In an internally electrically heated rb-z tary furnace, incombinationga revoluble furnace having an opening for the introductionof material and an opening for the removal of said material, means forrevolving the furnace, wire carrying means witliin the furnace, a Wirecarried thereon and extended outwardly of the fumace and means withinthe furnace whereby material introduced into lthe furnace through oneopening will be conveyed to the other opening.

4r- In an internally electrically heated roi tary furnace, incombination, a revoluble furnace having an opening. for the introductionof material and an opening for the removal of said material, means forrevolving the furnace, wire cari'yin means withinthe furnace, a wire.carried thereon and extended outwardly of the furnace and means withinthe furnacewliere'b'y the revolution of the furnace will cause materialintroducedA throu h the opening to bedelivercd through' t e otheropening. .l 5.' In an internally electrically heated 'ro1- tary funace,in combination a revoluble furnace having an `opening for the' introf.duct-ion of material and anl opening for the reinovalof said material,`-means for revolv-v ing the furnace, Wire carryin me'a'ns within thefurnace, awire carried t ereon anden-h tended outwardly of the furnaceand a helix y shaped member within the furnace' and carried therebycapable of conveying material from one end of the furnace to the otherduring the revolution of the furnace.

6. In an internally electrically heated rtary furnace, in cmbination',.al stationary shaft, a furnace revoluble around theshaft,means fornrevolving the furnace, means .for introducing material intothe-furnace, means for the `removal of material from the vfui"- nace,wire carriers within the furnace and spaced from theside thereof, a wirecarried thereby and extendingoutwardly ofthe furnace and meanswithinthefurnace'for the removal of introduced material during the'revolution ofthe furnace. a

7. In an internally electrically heated rotary furnace, in' combination,a stationary shaft, a furnace'revoluble' around the shaft,

means for revolving the furnace, means for introducing material into thefurnace, means within the furnace for removin ma# terial fromthefurnace, a plurality o elec-v `tric insulators capable of maintaining awire and a wire carried thereby and extending outwardly-of vthefurnace..

A 8. In'an internall electrically heated ron tary furnace, in comlinatioii, a hollow shaft, a furnace 'revoluble around the shaft, means.for revolving the' furnace, means external of the 4furnace forintroducing material t'hrofuglif-the-shaft into the furnace,openigfineans for Vallowing the removal of ma-I terial f rom:thefiirnace, electric insulators carried! by the shaftand capable of main--tainingfawire and an electric wire carried thereby.- and. extendingoutwardly through the shaft. Y

s. 9;In van internall electrically heated ro.- tary furnace, in comination, a hollow shaft, a furnace revoluble'around the shaft, means forrevolvingv the furnace, means external of Imi 'tar'ygfurnaca incombination@ honowehaft,

a furnace revoluble around the;sha'ft,means for revolving the furnace,means external. of the furnace. for introducing -materiial through theshaft into the"furnace,opening means for' allowing the removal ofmaterial from theV furnace, electric 'insulators carried by the shaftand capable of maintaining a wire, an electric wire carried tliereb.

and extending outwardly throughthe sha and means whereby the revolutionof the* furnace will cause material ,intr throu h theopening to bedeliveredt ough the eter opening. v if" 11. In arr internallyelectrically heated rotary furnace, in combination, a hollow shaft,

a furnace ,revoluble around the shaft, means for revolving the furnace,means' external of the furnace for introducing material c through vtheshaft finto the furnace, lopening means for allowing the removal of ma#Vterial from the furnace, electricjinsulators carried by the shaft andAcapable of maintaini a wire, an electric Wirecarried there# by anextending outwardly through the shaft; and a helix sha. ed memberwithin' the furnace and carri' Ythereby capable ofv conveying materialfrom one end of the furnace to the other during the revolution of thefurnace. 4

12. -,In anjinternally electrically heated rotary furnace, incombination, a revoluble furnace having an opening for theintroduc'ftion of material and an openingfor the-removal of saidmaterial, means for revolving the furnace, means for introducing a.

u ing outwardly through the'shaft.;

Y into the furnace during its'revolution, wire' carrying' means withinvthe furnace and a. wire carried thereon and extended outwardly of thefurnace.

13. vIn an internally electrically heated rotary furnace, incombination, a' hollow shaft, a furnace revoluble around the shaft,Ameans for revolving the furnace, means external of the furnace forintroducing material through 'the shaft into the furnace, opening meansfor allowingthe removal of material from the furnace, means for in:troducing a gas intothe furnaceduring its. revolution, electricinsulators carried by the shaft and capable of maintaining a wire andelectric wire carried thereby and extend- 14. In an internally.electrically .opening rotary'v furnace, in combination, a hollow shaft,a furnace revolublearigund the shaft, means for revolving the furnace,means external of thefurnace for i-,r-rtroducin material through theshaft the irnace, opening means for allowing the removal of materialfrom the furnace", means for introducing a gas into the furnace durin`its revolution, `electric insulatorsv carrie by -the shaftand capable.fof maintaining a wire, 'an electric wire carried thereby and extendingoutwardly through the shaft and means within the furnace wherebymaterial introduced; into the furnace through the opening will beconveyedto the other open- 15. Inlan internally electrically heatedrotary furnace, in combination, a stationary' pensating means forthelongitudinal expansion of the furnace due to the heating thereinf, wirecarriers within the furnace and 'spaced from the side thereof, a wirecarried thereby and extending outwardly of the furnace' and meanswithinthe furnace for the removal of intoduced material during the revolutionofthe furnace..l

-16. In an internally electrically heated rotary furnace; combination,laholl iw Shaft, a furxiarevoluble around the shaft, means for' revolvingthe `furnace, means exnalof theffurlace for introducing materialthrough-Stile into theI furnace, opening means' for allowngfthefremovalof material 'from the rnace, com ensating lmeans for the longitu inalexpansion of the furnace d ue to the heating there0f. elec'trcinsulators carriedby the shaft"V andfcapahie of maintaining a wireand-auf electric wire carriedthereby and extending 'outwardlythroughtheshaft. f

.717. 'In linternally -felectricallyheated v rotary ."furnace, .incombination, a hollow shaft, furnacerevoluble around the shaft, meansfor revolving the furnace, means external' of the ;.fo'r introducingmate rial through the"=shaft"i`nto the furnace,

opening means ifo'r allowing the removal of material Ifrom the` furnace,compensating meansfor the longitudinal expansion of the furnace due-tofthe Heating thereof, electric insulators ca rrielf'ay'the shaft andcapable of maintaining afwi'reL'an electric wire carried tllereliyf andHextending outwardly t'hrqughtheshaftand means wherebymaterial'introducedi'lito the furnace through one willbe conveyed to theother open rotary Cfurnace. Ain. jcomhinatiomfa hollow4 fternaljfof ,thefurnacefor jintroducing maglie-4 Lacasse ,rialA through the shaft intothe furnace,

v insulators carried bythe shaft-and capable of maintaining a wire, anelectric wire car- -ried thereby and extending outwardly throughthe'shaft and means whereby the' introducedthrough one openin livered-tlirough the other ope g 'rotary Afurnace, in combination, arevolubleduciu material into the furnace having an opening for theintrofallow revolution of Vthe furnace will cause material to be demng.

. I9. In aninternally electrically heated duction of -material and anopening for the removal of saidmaterial, means for revolvfurnace, meansexternal of the furnace for Introducing materialthrough the shaftinto-ingthe furnace, wire carryin means within the furnace, a 'wire carriedt ereonand extended outwardly of the furnace and an external covering ofheat insulating material carried by the furnace.

20." In an internally electricallyheated' rotary' furnace, incombination, a hollow a furnace revoluble around stationary sha thehollow sha means for revolving the the-furnace," means for allowing theremoval electric insulators carried by the shaft and spaced from the-side ofthefurnace'a wire wound\ around the insulators and carriedthereby, `the extremities of'the wire extending outwardly ofthe furnaceandan'extern'al covering of-'heat insulating material carried by thefurnace'.

2]'. In an internally' electrically heated rotary furnace, Aincombination,` a hollow stationary shaft,` a furnace revoluble aro`undthe hollow shaft, means for revolving the' furnace, means external ofthe furnace for introducing material through the shaft into th(`furnace, means for allowing the removal of material from the furnace,means where- -hy material introduced into the furnace at one end will beconveyed to the other end a plurality of electric insulators carried bythe shaft and spaced from the side of the furnace, a wire woundaroundthe insulators and carried thereby, the extremities of'th'e wireextending outwardly of the furnace and an external covering of heatinsulating material carried by the furnace. e

22. In an internally electrically heated rotary furnace, in combination,l a hollowtricallynheating the of material from the furnace, a pluralityof' 25.

acca-'ie assumes carried by the shaft 'and spaced from the side ofthefurnace, a wire wound around the insulators and carried thereby. theextremities of the wire extendfurnace. chamber therewitlf, means forrevolving the side memberh'lmeaus for of -theremovalof .a `.'inaterialfrom within e furnace and means internal 'ofthe furnace for electricallyheat' the same.-

electrically heated rnace, means fon-'5 24.111 an internallylelectrically heated-- .rotary furnace, in combinatie two station-"1revoluble-f between theend'members and forming .a

ary en d members, aside mem furn'be chamber therewith, means forrevolving the side member, means .for-"lintroducing 'material into thefurnace, revoluble means forremoving material vfrom within the furnace,means for 'allowing ofthe removal of .a-material from within the furnaceand means internal of the furnace forleleca'n internall felectricallyheated rotaryffurnace, in com ination two stationary end member's,`aside member .revoluble between theend members and forming'a furing theside -member, means for introducing material into the furnace, meanswhereb -nace chambertherewith, means for revolv the revolution of theside :member w' l'.

causernaterial to beconveyed'from one end of the -furnace to the other,means for allowing of the removal of amaterial from with? ing thefurnace\ .and .means internal ofthe furnace for electrically-heating thesa'me.

` 26,1@ an internally electrically heated rotaryv furnace, incombination two stationary end members, a side member revoluble betweenthe end members and forming a furnace -chamber therewith, means forrevolving the side member, means for introducin fmaterial into'thefurnace, a helix shape ried thereby capable of conveying material fromone end of. the /lrnace to the other during the revolution of thefurnace and' means internal of the furnace for elecrcallv heating` thesame.

27. In an' internally' electrically heated rotary furnace, incombination, a stationary hollow shaft, two stationary end members, aside member revoluble between the cnd vmembers and forming a furnacechammember within the furnace and carlas ber therewith, means forrevolvgiug the side member, means external of the rnace for introducingmaterial through the shaft and into the furnace` means for.allowing' theremoval of material from the furnace, elecmember, means externalof thefric insumos within the furnace spad from the side member. and anelectric wire carried by the insulators and extending out- 4wardlyof thefurnace. Y Y

Y introducing material through the shaft and vinto the furnace,'m'ea'nsor allowing the removal of material from `the furnace, elec other opetric insulators within thefurnace spaced'. from the side member, anelectric wire car- Y.

ried by the insulators and extendi outwardl of the furnace and meanswereby introduced intol the furnace.

material through lone opening will be conveyed'to the umg. y

29.'In an internall rotary hollow shaft, two stationary end members,

a side member revoluble between the-end; members andforming a furnace'chamber therewith, .means for revolving l the side member, meansexternal of the urace -for introducing material through the shaft andinto the furnace, means for allowingv the renieyal of material from thefurnace, elecfrom the sidgmember, an electric wire car Y a sidemembergrevolublebetveen the end ried by the .insulators and extendinout- `wa'rdly of tli*V furnace andnieans w ereby, the' revolution of thesidemember will cause material introduced through the openng`to.befdelivcred through the delive end.

30. In an internally electrica ly, -heated rotary furnace, incombination two stationary end members, a side member revoluvble betweenthe end members and'forming a furnace chamber therewith, means for revvolving the sidel member, means for introducing material ii'itothelfurnaeemeans.for

allowing of the removal of a material-from 'I 'within the furnace, meansinternal offtlie furnace .for electrically heating` ,.tne "same and 'anexternal coveringfof heat'insulating material carried bythe evice. l, Y31 In an internally'. electrically; heated 'rotary furnace, incombination, two s ta the y side.

electrically heated furnace, in com ination, a stationary tion .ofthesideA member will cause 4material Y to-be 4conveyed from one end of thefurnace to the oth introduci4 material throu h the' shaft the furnacetothe other therethrough.,` e

- of 4th,.day of Octbber, 1922.

tionar'y end members, aside member revoluble between .the end membersand forining a furnace chamber'` therewith, means for 66' .revolvingtheside member, means -for introducing material'into the Vfurnace, meanswhereby the revolution of the side member will .cause material f tobeconveyed from;

one end of the furnaceto the other, means 60 for allowing' of theremoval of a, material from withinA the furnace, means internal 0i 'thefurnace for electrically heating thev intrdwingmariai through the-shaft,md 'into the furnace# means'fd'r. allowing the removal of material thefurnace', electric 76 insulators within .thefi'irnace spaced from' the,side `ine`inbci","an electric wire carried by the insulators.and-extending 'outwardlyof' the furnace and means whereby the revolu-33.11- an 'neftali "eitceiauy haan rotary furnace, in com ination, astationary hollow shafigitwo1 stationary j'eiid members;

membersl and forming a' fuce chamber therewith, means for revolvin thesidev member, -means external, of the urnace 'for into the ace, means orlallowing the removal: of material fromthe furnace, elec -tric A'insulators within thev furnace spaced from theside member, anelectric'wire carried -byhe insulators andextendng outos wardly. o thefurnace,.and means whereby the revolution ofthe sidemember will-causematerialto be .conveyed from one end of end and delivery l i 10oSlignedat New York. city, in the county ew York ancLState' of New York,this -EDWIN L WILLSON.

